Sewer Gas Smell after Roots removed

We were getting a sewer gas smell out of the floor drain in the basement.

This usually means our sewer line between the house and the street has roots building up. If you look in the clean out line at the front of the house, in the basement, you can see standing grey water when this is happening.

We had the line rotor rootered and got a big hunk of roots (and other stuff) out.

The line is now empty of standing water.

But! The sewer gas smell will not go away (it has been two days). The only place I smell it in from the floor drain in the basement. There is water in it and I have flushed it with lots of water, lots of bleach, even boiling hot water.